Hcl to dissolve tin

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Yggdrasil said:
The AR itself is not interesting in this setting, even though the milkiness may be from Metastannic acid.
Did the powder change after the AR?
The Metastannic acid in this setting would have formed in the Nitric stage.
Metastannic acid is notoriously hard to filter so it should be very obvious that it is that.
Te finest particles may go through, what kind of filter do you use?

Edit for clarity
Click to expand...
Yes, it is possible that finest particles go through the filter when solution is hot i filtered using my regular method of nylon cloth (thick ) that is also called PP filter cloth.

Powder is quite same after AR.
Only white powder residue remains on filter.

If finest particles goes through filter how they precipitate with gold?
 
Sunnyket said:
Yes, it is possible that finest particles go through the filter when solution is hot i filtered using my regular method of nylon cloth (thick ) that is also called PP filter cloth.

Powder is quite same after AR.
Only white powder residue remains on filter.

If finest particles goes through filter how they precipitate with gold?
Click to expand...
Better use proper filters, and if you did not dissolve Knife handles and hollow Silver ware, there really should not be any Tin.

I would not trust XRF much on powders.

If it filters relatively easy it could be Silver Chloride.
Do it darken in the sun?

I'm not entirely sure I understand what you mean here:
If finest particles goes through filter how they precipitate with gold?
Click to expand...
If there are fine particles, it should not be Gold, Gold will be dissolved in the liquid and maybe locked into the mud,
especially if it is fine AgCl particles, bigger AgCl "sand" can lock up some Gold, but they will not pass the filter.
 
Yggdrasil said:
Better use proper filters, and if you did not dissolve Knife handles and hollow Silver ware, there really should not be any Tin.

I would not trust XRF much on powders.

If it filters relatively easy it could be Silver Chloride.
Do it darken in the sun?

I'm not entirely sure I understand what you mean here:

If there are fine particles, it should not be Gold, Gold will be dissolved in the liquid and maybe locked into the mud,
especially if it is fine AgCl particles, bigger AgCl "sand" can lock up some Gold, but they will not pass the filter.
Click to expand...
Yes i tried buchner funnel filtration setup but it didn't worked well for me. And took lots of time.
PP filter cloth i used many times and it works 95-98 % efficiency.
Please suggest any better filter process (low cost setup).

Yes hollow silver material was there.

Not much easy it took 4-5 hours for total filtration of approx 1000ml-1200ml

"Finest particle goes through filter means"
I mean to say the tin dissolved or fine particles of tin passed through filter and when added SMB they precipitate with gold and gold is locked into mud.

Currently all the material dried/roast well looks like
 

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Sunnyket said:
Yes i tried buchner funnel filtration setup but it didn't worked well for me. And took lots of time.
PP filter cloth i used many times and it works 95-98 % efficiency.
Please suggest any better filter process (low cost setup).

Yes hollow silver material was there.

Not much easy it took 4-5 hours for total filtration of approx 1000ml-1200ml

"Finest particle goes through filter means"
I mean to say the tin dissolved or fine particles of tin passed through filter and when added SMB they precipitate with gold and gold is locked into mud.

Currently all the material dried/roast well looks like
Click to expand...
If it is roasted it should dissolve in HCl.
If not, it could be SilverChloride.
 
When heated to cherry red, stannous chloride converts to stannous oxide, which can then be dissolved with hot HCL. Be patient, as it can take a fairly large volume to clean it thoroughly.
The dissolved tin oxide will appear bright yellow in the HCL rinse. Continue rinsing until the yellow disappears.
Hope this helps.
 
dtectr said:
When heated to cherry red, stannous chloride converts to stannous oxide, which can then be dissolved with hot HCL. Be patient, as it can take a fairly large volume to clean it thoroughly.
The dissolved tin oxide will appear bright yellow in the HCL rinse. Continue rinsing until the yellow disappears.
Hope this helps.
Click to expand...
Why would we want to transform Stannous Chloride??
I believe what you mean is Metastannic acid not Stannous Chloride.
 
I actually sent in some drill samples from a strange bar I had in.
The following is our findings from the 3g sample you sent recently.
Ag .057/056
Tin 82.9%
Copper 10.3%/
It went into a nitric acid solution without any problems and I found the silver content.
It did produce a lot of white sediment but that filtered without a problem.
None of the jelly-like substances that have been blocking my filters for ten years.
Unfortunately a bonus for the base metal dealers not a potential job for me.
Wish I could afford better testing equipment.
 
I thought I'd give NaOH a try to dissolve the solder of a circuit board. I even found this bit of chemistry:

There are five amphoteric elements (metals) in the periodic table Be, Al, Zn, Sn, Pb
Pb + 2NaOH + 4H2O -> Na2[Pb(OH)6] + 2H2 (Sodium plumbate)
Sn + 2NaOH + 4H2O -> Na2[Sn(OH)6] + 2H2 (Sodium Stannate)

Unfortunately, it didn't work. I then read that it wasn't the metals but the oxides (PbO and SnO) that dissolved in NaOH. I added some H2O2 as an oxidiser. Nothing happened. I warmed it up. Still nothing happened.
Despite the preference for HCl, there are some hints/mentions that NaOH does dissolve solder whether it is tin/lead or tin(with a bit of copper and selenium).

I know I'm barking up the wrong tree, but has anyone actually dissolved any kind of non-silver solder with NaOH?
 
Last edited:
Nigel said:
I thought I'd give NaOH a try to dissolve solder of a circuit board. I even found this bit of chemistry:

There are five amphoteric elements (metals) in the periodic table Be, Al, Zn, Sn, Pb
Pb + 2NaOH + 4H2O -> Na2[Pb(OH)6] + 2H2 (Sodium plumbate)
Sn + 2NaOH + 4H2O -> Na2[Sn(OH)6] + 2H2 (Sodium Stannate)

Unfortunately, it didn't work. I then read that is wasn't the metals but the oxides (PbO and SnO) that dissolved in NaOH. I added some H2O2 as an oxidider. Nothing happened. I warmed it up. Still nothing happened.
Despite the preference for HCl, there are some hints/mentions that NaOH does dissolve solder whether it is tin/lead or tin(with a bit of copper and selenium).

I know I'm barking up the wrong tree, but has anyone actually dissolved any kind of non-silver solder with NaOH?
Click to expand...
I have not been up that particular tree, as HCl has served me well so far.
But I think it depends on concentration and temperature.
 
I have some copper flat pieces that were sent to me - they have what looks like a layer of tin on them. maybe they were electrical related parts.

what would be the best way to dissolve the layer to leave the Cu ? Hot HCl or another method ?

Just curious on this.

Thanks.

GOG
 

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